Case closed, Ms Cornwell: Jack the Ripper killed Diana

Patricia Cornwell is not only the world's bestselling crime writer. She is also the author of a book that conclusively "proves" that Jack the Ripper was really the well-known painter Walter Sickert. Not content with that, she has now turned her attention to the mystery of how Diana, Princess of Wales, met her death, and will soon be showing a programme on American TV that reveals her findings.

But you don't have to wait till then to learn the truth.

For I, too, by a fantastic coincidence, have been investigating the death of Diana, and I have come to an almost unbelievable conclusion.

I believe that Sickert was not only the true Jack the Ripper, but that he was also responsible for Diana's death.

Incredible?

Of course.

But impossible?

I do not think so.

Let us examine the evidence.

Sickert was born in 1860 and "died" in 1942, long before Diana was born. That seems at first sight to eliminate him from the suspects. But Sickert was a man who was always seeking to stay young. He hated the idea of growing old. Nor did he want his pictures to age. He spent most of his days in his studio mixing paints, trying a bit of this with a bit of that. Like all painters, he sought mixtures which would never fade, never grow old on the canvas. It is not beyond the bounds of possibility that, one day, he stumbled across a potion with rejuvenating properties for humans also.

Ah, you will say, but if he were to discover such a thing, he would shout it from the rooftops!

I do not think so. I think that if any of us discovered the secret of eternal youth, we would not mention it to a soul.

And, significantly, Sickert never mentioned such a thing to anyone.

So we have the overwhelming likelihood of an ageless painter who has discovered the potion of youth, who will never die and who, as we know from Cornwell's previous book, was already a mass murderer. He "died" in 1942. But 1942 was the middle of the war, a confused time when it would be child's play to fake one's death in an air raid. And so Sickert, mass murderer, takes on a new identity.

But mass murderers never quite give up their little habits, do they? And maybe by the 1990s things were getting a little boring for this 130-year-old painter. Perhaps he thought he would try another little crime before bedtime. Maybe he would murder... one of the highest in the land!

But what could be his motive? Why would he want to murder the world's darling, the people's princess, the Queen of Hearts?

Well, do not forget that Sickert was not English by birth. He was German. (A very German name, Walter Sickert.) He came to England as a young man, learned English and was an actor for some years, before taking up painting. He must have felt at home here. After all, the British royal family is also German! So it is easy for a German to melt into the furniture in England.

But when, as a very old man, he sees the Princess of Wales in danger of marrying an Egyptian called Dodi, his Teuton pride returns to the surface. How could the most senior woman in the family, after the Queen, possibly marry a non-German, and someone so very defiantly non-German?

Ganz unmöglich.

So he determines to wipe out the threat in blood.

For a man who has already done all the Jack the Ripper murders, this is not a hard decision. Of course, he is now very old. But thanks to the youth potion, he can masquerade as a young man. And he trained as an actor, remember! So there is the 130-year-old painter, masquerading as a young man driving a car. Driving a car just behind the royal party. Into the underpass, edging up behind the royal car, where he nudges it and lets the unwary chauffeur do the fearful rest. (A chauffeur, I may say, for whom Sickert has been buying drinks not an hour before in the hotel bar.)

If what Diana's ex-butler, Paul Burrell, has been saying is true, Diana also had a presentiment that the murderous artist was on her track. The name she suspected has been blacked out in the incriminating letter, but I think we all know of whom she was in deadly fear.

Walter Sickert.

Or the artist formerly known as Jack the Ripper.

I shall be interested to see if Ms Cornwell has any different ideas on the subject.